Method and apparatus for determining sliding resistance

Abstract

A method and apparatus are disclosed for determining sliding resistance between a surface of a portion of a glass section and a surface of a strip of resilient material, such as an elastomeric weatherstrip, which defines a channel having a longitudinal axis. The apparatus includes a plate which is slidably engaged with a platform and structure for rigidly securing at least one strip of weatherstrip to the plate. Further included in the disclosed apparatus is a device for exerting on the glass section a plurality of forces relative to gravity so that the portion of the glass section passes at a selected rate through the channel along the channels longitudinal axis. Friction between the surface of the glass section and surface of the strip of resilient material results in a portion of the exerted force being transmitted to the plate. A force measuring device, which is coupled to the platform, measures the portion of the force exerted on the glass section that is transmitted to the plate. The disclosed method of the invention includes the steps of securing at least one strip of resilient material to a plate so that force exerted on the strip is transmitted to the plate and exerting on a glass section a force so that a portion of the glass section passes at a selected rate through a channel defined by the strip of resilient material. A portion of the force exerted on the glass section which is transmitted to the plate by friction between the surface of the glass section and the surface of the strip of resilient material is measured and represents sliding resistance.

What is claimed is: 
     
       1. An apparatus for determining the sliding resistance between a surface of a portion of a glass section subject to a force exerted by gravity and a surface of a first strip of resilient material, the surface of the strip of resilient material defining a channel having a longitudinal axis, the apparatus comprising a plate slideably engaged with a platform,   means for rigidly securing the first strip of resilient material to said plate so that force exerted on the strip is transmitted to the plate;   means for exerting on the glass section a plurality of forces relative to gravity so that the portion of the glass section passes at a selected rate through the channel along the channel's longitudinal axis according to the respective one of the plurality of forces then applied, friction between the surface of the glass section and the surface of the strip of resilient material resulting in a portion of the force then applied being transmitted to the plate; and   means coupled to the platform for measuring the portion of the then applied force that is transmitted to the plate.   
     
     
       2. An apparatus as set forth in claim 1 further comprising means for rigidly securing to the plate a second strip of resilient material defining a channel having a longitudinal axis so that the longitudinal axes of the channels defined by said first and second strips are arranged to be parallel to one another, the glass section being arranged so that separate portions of the glass section pass through each channel simultaneously. 
     
     
       3. An apparatus as set forth in either of claim 1 or claim 2 wherein said means for exerting on the glass section a plurality of forces comprises a motor which rotates a spool, and   a line which is wound around said spool and which is connected to the glass section, rotation of said spool in a first direction resulting in said line being wound around said spool and thereby exerting a first of said plurality of forces on the glass section, the first force being greater than and counter to the force exerted on the glass section by gravity, and rotation of said spool in a second direction resulting in said line being unwound from said spool, and thereby exerting a second of said plurality of forces on the glass section, said second force being less than the counter to the force exerted on the glass section by gravity.   
     
     
       4. An apparatus as set forth in claim 1 wherein said means for measuring the portion of the then applied force transmitted to said plate is a strain gage coupled at one end to the platform and at an opposite end thereof in communication with said plate. 
     
     
       5. An apparatus as set forth in claim 1 wherein said means for rigidly securing the strip of resilient material is configured to orient the channel relative to vertical. 
     
     
       6. An apparatus as set forth in claim 1 wherein said means for rigidly securing the strip of resilient material is configured to orient the channel angularly offset from vertical. 
     
     
       7. An apparatus as set forth in claim 6 further including, means for determining the extent to which the channels are angularly offset from vertical.   
     
     
       8. An apparatus as set forth in claim 7 wherein said means for determining the extent to which the channels are angularly offset from vertical is a protractor the orientation of which is related to the orientation of the channel. 
     
     
       9. A method for determining the sliding resistance between a surface of a portion of a glass section subject to a force exerted by gravity and a surface of a first strip of resilient material, the surface of the strip of resilient material defining a channel having a longitudinal axis, the method comprising the steps of: securing to a plate which is slideably engaged with a platform a first strip of elastomeric material so that force exerted on the strip is transmitted to the plate, said first strip of elastomeric material forming said first strip of resilient material;   exerting on the glass section a plurality of forces relative to gravity so that the portion of the glass section passes at a selected rate through the channel along the channel's longitudinal axis according to the respective one of the plurality of forces then applied, friction between the surface of the glass section and the surface of the strip of resilient material resulting in a portion of the force then applied being transmitted to the plate; and   measuring the portion of the then applied force that is transmitted to the plate.   
     
     
       10. A method as set forth in claim 9 further comprising the step of securing to the plate a second strip of resilient material defining a channel having a longitudinal axis to the plate so that the longitudinal axes of the channels defined by said first and second strips are aligned to be parallel to one another, separate portions of the glass section being passed through each channel simultaneously. 
     
     
       11. A method as set forth in claim 10 further comprising the step of orienting said first and second strips relative to vertical.   
     
     
       12. A method as set forth in claim 10 further comprising the step of orienting said first and second strips angularly offset from vertical.   
     
     
       13. A method as set forth in claim 9 wherein the step of exerting on the glass section a plurality of forces is performed by rotating with a motor a spool, a line being wound around the spool and connected to the glass section so that rotation of the spool in a first direction results in the line being wound around the spool and thereby exerting a first of said plurality of forces on the glass section, said first force being greater than and counter to a force exerted by gravity, and rotation of the spool in a second direction resulting in the line being unwound from the spool and thereby exerting on the glass section a second of said plurality of forces, said second force being less than and counter to gravity. 
     
     
       14. A method as set forth in claim 9 further comprising the step of orienting said first strip relative to vertical.   
     
     
       15. A method as set forth in claim 9 further comprising the step of orienting said first strip angularly offset from vertical.